WO 2012/051134 A1 and WO 2011/153185 A1 describe rear spoiler systems in which, inter alia, air-guiding surfaces extending along a portion of the vertical height of the box-type structure are attached on the side walls; in addition, corresponding air-guiding surfaces are attached on the roof. The air-guiding surfaces reach over the blunt end of the box-type structure. The outer surface of the air-guiding surfaces extends from the front edge of each air-guiding surface toward the rear, initially transversely toward the outside or vertically upward, whereby the overall cross-section of the vehicle is increased, and extends slightly inwardly behind the rear surface of the vehicle. The air-guiding surfaces fixedly rest against the flat side surfaces or the flat top surface of the box-type structure.
US 2013/0106136 A1 describes a rear spoiler system, which is attached on the roof surface, rests at its front end on the roof surface and subsequently extends upward with a curvature in order to cover a rear edge of the rear-door frame. The air-guiding element rests on this edge. US 2013/0076064 A1 also shows such a system in which air-guiding surfaces are attached on the roof surface and on the side surfaces, wherein the air-guiding surfaces are displaceable, in particular retractable and extendable.
Therefore, in general, the air-guiding surfaces rest against the side surfaces or the roof surface of the box-type structure, some of which additionally rest against the rear edge, in order to be supported there.
DE 10 2009 014 860 A1 shows a rear spoiler device comprising a displacement device. It comprises air-guiding elements for lengthening the contour and for the aerodynamic air guidance of the side walls and the roof, which elements, in a home position, are folded in toward the rear doors and, in the travel position or the operative position, are raised up or extended and are supported on fastening elements of a rear vehicle edge. Such rear spoilers are used for improving the aerodynamics of the vehicle and can therefore reduce fuel consumption.
DE 20 2009 014 476 U1, DE 20 2009 014 510 U1 and DE 20 2009 015 009 U1 show further rear spoiler devices in which the air-guiding elements or spoiler elements are disposed so as to be displaceable or swivelable in order to allow for unobstructed opening of the rear doors.
Rear spoilers that are connected to hinges of the rear doors are also known. DE 102 28 658 A1 shows different flap solutions in which flat surfaces, which are swivelable by means of a hinge, are intended to provide for an aerodynamic optimization in the driving mode.
Such connections of the air-guiding elements in the hinge region are generally complex, however, and are limited to special hinge designs. In addition, the length of the usable air-guiding elements is generally limited. When the rear doors are swiveled open by 270° toward the front, relatively complex rear spoiler designs, in particular when used in the hinge region, can often adversely affect the swivel-open process.
In addition, the handling for the displacement from the home position into the travel position and also for the return thereto is generally labor-intensive. In addition, complex locking mechanisms are often provided in order to ensure sufficient stability of the different air flows and air vortices. These systems often have a quite complex design, on the one hand, and, on the other hand, are complicated to adjust. In addition, the functionality of the vehicle, in particular its accessibility as well, is somewhat limited.